Process for the preparation of water-insoluble azo-dyestuffs

ABSTRACT

Process for the preparation of a water-insoluble azo-dyestuff having particularly good qualities for printing by adding in the coupling process an auxiliary comprising a mixture consisting essentially of a primary aliphatic amine and/or a salt thereof with a low-molecular weight fatty acid, and of an aminoxide or phosphine oxide which contains a long-chained hydrocarbon radical.

United States Patent [72] Inventors OskarBraun Frankfurt am Main;Reinhold Deubel, Kelkheim, Taunus, both of Germany [21] Appl, No.702,184

[22] Filed Feb. 1, 1968 [45] Patented Sept. 21, 1971 [73] AssigneeFarbwerke Hoechst Aktiengesellschaft Vormals Melster Lucius & BruningFrankfurt am Main, Germany [32] Priority Feb. 4, 1967 3 3 Germany [3 l F51442 [54] PROCESS FOR THE PREPARATION OF WATER- [NSOLUBLE AZO-DYESTUFFS 7 Claims, No Drawings [52] U.S. Cl 260/176, 96/33, 96/563, 260/144,260/570.9, 260/583 D, 260/606.5 P 51 Int. Cl 5:091; 35/04, G03f 7/100[50] Field of Search 260/144, 160,176, 178,193, 203, 204, 205, 206, 207,207.1

Primary Examiner- Floyd D. Higel Attorney-Curtis, Morris & SaffordABSTRACT: Process for the preparation of a water-insoluble azo-dyestuffhaving particularly good qualities for printing by adding in thecoupling process an auxiliary comprising a mixture consistingessentially ofa primary aliphatic amine and/or a salt thereof with alow-molecular weight fatty acid, and of an aminoxide or phosphine oxidewhich contains a long-chained hydrocarbon radical.

in recent years, a fundamental change has been observed in the art ofgraphic printing. With a view to increasing the production capacity,more and more fast running printing machines are used, a fact whichcauses at the same time a considerable increase in the requirements thatprinting inks and the pigments incorporated in these inks have to meet.The pigments have to meet above all two demands: the azo-dyestuff musthave as high a tinctorial power as possible and at the same timeparticularly good rheologic properties, so as to obtain, considering thelow transfer of printing ink by the color furnisher in fast runningmachines, still intense prints. The standard pigments hitherto used forprinting inks no longer meet these steadily growing demands. Attemptsare therefore made to prepare water-insoluble azo-dyestuffs of hightinctorial power and good rheologic properties by modifying theconditions of manufacture and by the use of suitable additives.

Thus, for example, in Belgian Pat. No. 660,978 a process for themanufacture of easily dispersible pigments showing an increasedstability of flocculation is described, wherein there are added to thepigment moistened with water 8 to 25 percent of a long-chained aliphaticamine or a corresponding salt, which salt being converted completely orto a large extent into the free amine prior to filtering and drying ofthe pigment. According to the Examples 1 to 4 of said Specification,which concern azo pigments, the amines or the amine salts are added onlyafter coupling has been carried through and the coupling mixtures,before adding the amines, have been heated for several hours totemperatures ranging from 70 to 90 C. After addition of the amines thetemperature of the mixture is maintained for several hours at 80 to 90C. The pigments thus obtained show, especially in the yellow series, aclear shifting from bright greenish to intense reddish shade, incomparison with pigments prepared without amines.

Furthermore, U.S. Pat. No. 3,120,508 publishes a process for themanufacture of water-insoluble azo-dyestuffs of high tinctorial strengthaccording to which small amounts of surface-active salts of primaryaliphatic amines with carboxylic acids are added during the couplingprocess, whereafter coupling is carried out as usual. Though pigments ofhigh tinctorial strength can be prepared by this process, theazodyestuffs thus obtained do not meet the demands of today as to theirrheological properties in the printing inks.

It has now been found that it is possible to prepare water-insolubleazo-dyestuffs having particularly good qualities for printing by addingin the coupling process a mixture of aliphatic amines and/or thecorresponding salts, and ofa longchained hydrocarbon radical containingamine oxides or phosphine oxides in quantities of l to 35 percent,preferably of3 to 17 percent, referred to the weight of the dyestuff.The mixing proportion of the aliphatic amine and/or its salt and theamine oxide or phosphine oxide in the auxiliary agent used may varywithin wide limits. Thus, according to the process of the presentinvention, auxiliaries are used, the mixing proportion of which ofaliphatic fatty amine and/or its salt lies between 95 and 50 parts byweight, preferably between 95 and 70 parts by weight, and of amine oxideor phosphine oxide, complementary each time to 100 between 5 and 50parts by weight, preferably between 5 and 30 parts by weight.

By adding, according to the process of the present invention, theaforementioned mixtures of auxiliaries in the coupling process,dyestuffs can be obtained, having particularly good properties forprinting, that means, the printing inks made therefrom have anextraordinary fluid consistency which proves extremely favorable at thevery rapid printing speed. Thus, dyestuffs which normally cannot be usedfor graphics or only to a limited extent can be converted, according tothe process of the present invention, into inks having good printingproperties and thus being generally applicable even in this field.Besides excellent rheologic properties the dyestuffs thus obtained havea distinctly higher tinctorial power compared to those products obtainedwithout the aforementioned additions, and without there being anyimportant shifting of shade, for instance in the yellow series from thebright pure greenish to an intense reddish tint. The dyestuffs have thefurther advantage of being more lustrous and more transparent, Suitablealiphatic amines are, in the first instance, compounds of the formula inwhich A represents a direct linkage or the radical C,.H or C,.H2n 2, nrepresents zero or a number from 7 to 22, m is zero or a number from 1to 6 and p represents the .number 2 or 3, but n and m may not be zero atthe same time. Mixtures of the above-mentioned amines may also be used.it is often of advantage to use the amines together with amine salts,preferably with the salts of these amines with low molecular weightfatty acids, such as formic acid. acetic acid, propionic acid, lacticacid or oleic acid.

As amines there may be used in the mixing components of the auxiliary,according to the present invention, for example capryl amine, laurylamine, palmityl amine, stearyl amine, oleyl amine, arachyl amine,behenyl amine as well as tallow fat amines and coconut oil aminesobtainable from fatty acid mixtures occurring in nature. As diandpolyamines, there may be mentioned for example ethylene diamine,propylene diamine, tallow fat ethylene diamine, tallow fat propylenediamine, coconut oil ethylene diamine, stearyl triethylene tetramine,diethylene triamine, pentaethylene hexamine and dipropylene triamine.

As aminoxides or phosphine oxides, there may be mentioned, according tothe present invention, compounds of the general formula wherein Xrepresents a nitrogen or phosphorus atom, R, represents a hydrocarbonradical containing a long aliphatic chain, R and R each represent alkyl,cycloalkyl, aryl or am!- kyl radicals. The radical R may represent analiphatic hydrocarbon radical in a straight or branched chain,containing 8 to 22 carbon atoms and, if desired,'one or several doublelinkages. R may furthermore represent an aromatic radical with at leastone aliphatic side chain of about 4 to 12 carbon atoms. The radicals Rand R; can be identical or different and, if desired, they can alsocontain substituents, such as for example, halogen atoms, hydroxyalkylor polyalkylene ether groups. The radicals R and R preferably representalkyl radicals containing 1 to 5 carbon atoms. There may, however, alsobe mentioned compounds in which one of the radicals R or R contains along aliphatic chain. Such compounds thus contain two hydrocarbonradicals with a long aliphatic chain in the molecule.

As mixing components of the aminoxide or phosphine oxide series suitablefor the process of the present invention, there may be mentioned forexample: dodecyl-dimethyl-aminoxide, oleyl-diethyl-aminoxide,lauryl-methyl-ethyl-aminoxide, coconut oil dimethyl-aminoxide, coconutoil-dipropylaminoxide, coconut oil methyl-benzyl-aminoxide,oleylpropyl-methyl-aminoxide, dodecyl-ethyl-cyclohexyl-aminoxide, tallowfat dimethyl-aminoxide, dodecyl-dimethyl-phosphine-oxide,dodecyl-diethyl-phosphine-oxide, dodecylmethyl-ethyl-phosphinc-oxide,dodecyl-methylbenzyl-phosphine-oxide, oleyl-dimethyl-phosphinc-oxide,oleyl-dibenzylphosphine-oxide, tallow fat-dimethyl-phosphine-oxide andcoconut oil diethyl-phosphine-oxide.

The process of the present invention can be applied to the manufactureof known water-insoluble azo-dyestuffs. For example, azo dyestuffs ofthe following groups may be mentioned:

Azo pigments of the ice color series without solubilizing groups whichare formed by reaction of monoor polyvalent bases as diazo componentswith coupling components, for example, aromatic hydroxy compounds, e.g.B-hydroxynaphthalene, or hydroxyaryl-carboxylic acid arylides, forexample, -hydroxy-anthracene carboxylic acid anilide or couplingcomponents which are derived from carbazole or benzocarbazole, oracetoacetyl-amino compounds which can be enolized or pyrazolones.

The mixtures of aliphatic mines and/or their salts and of a long chainhydrocarbon radical containing aminoxides or phosphine oxides used asauxiliary according to the present invention can be added in any stageof the coupling, whereby the singlecomponents can be mixed previously totheir being added, or they can be added separately one after the otheror at different intervals. Thus, the additives can be incorporated forexample into the solution or dispersion of the diazo component or theycan be added simultaneously with the diazo component, but separately, tothe coupling component. Furthermore, the mixtures of the auxiliary canbe added to the precipitating acid, for instance, acetic acid, by whichthe coupling component having dissolved under alkaline conditions, isprecipitated. It is also possible, to add the mixtures used according tothe process of the present invention, only after precipitation of thecoupling component or at a later stage of the coupling process, such asfor instance during the heating operation. Likewise, for example, thealiphatic amine and/or its salt can be added to the coupling componentpreviously to the addition of the diazo component and the aminoxide orphosphine oxide may be added later in the course of the coupling, as forinstance during the heating up. Another possibility consists in addingthe aminoxide or phosphine oxide first, that is to the suspension of thecoupling component, and in proceeding with the aliphatic amine or itssalt in a later period of coupling, for example during the heatingoperation. According to the process of the present invention, the mixedcompounds of the auxiliary can be added either in form of an aqueousemulsion, or dissolved in an organic acid, such as for example aceticacid, or even molten to the coupling liquor at elevated temperature of,for example, 60 C. The pigment dyestuff obtained frequently in a tine,difficulty filterable dispersion can be converted into a well filterableform, when aqueous alkalies are added to the coupling suspension priorto filtration.

The following Examples illustrate the invention, but they are notintended to limit it thereto. The parts and percentages being by weightunless otherwise stated.

EXAMPLE 1 A tetrazonium salt solution prepared in known manner from 76parts of 3,3-dichloro-4,4'-diamino-diphenyl is added dropwise, within 2hours, to a coupling component, which was obtained by dissolving l l 1parts of acetoacetylamino-benzene in 3,000 parts of water and 114.5parts of a 33 percent sodium hydroxide solution and precipitated byaddition of 63 parts of acetic acid. The coupling mixture is then heatedto boil within 45 minutes. As soon as the temperature attains 60 C., amixture heated to 65 C. and consisting of 27.2 parts of tallow fatpropylene diamine and 10.0 parts of an aqueous solution of coconut oildimethyl-aminoxide of 30.4 percent strength is added. The whole isboiled for 15 minutes, cooled with water to 80 C. and then 150 parts ofa33 percent sodium hydroxide solution are added. After having stirred forminutes more, the product is filtered, washed to neutral and thedyestuff is dried at 60 C. and ground subsequently, as usual.

The test for suitability for industrial application of the dyestuff thusobtained is carried out with a commercial intaglio printing varnishbased on a phenol resin and toluene and having a solid matter content of50 percent. The printing ink which consists of 12.5 percent ofazo-dyestuff, 22.5 percent of toluene and 65 percent of theabove-mentioned varnish is ground for minutes at a speed of 400rev./min. in an attritor, the grinding unit of which having a diameterof 3 mm. The printing ink thus prepared is highly fluid, that means itcan be poured quickly from a beaker. A printing ink prepared inanalogous manner with a pigment which had not been coupled with theadditives according to the present invention is, on the contrary, highlyviscous and strongly thixotropic and cannot be poured from an invertedbottle.

In order to determine the tinctorial strength, the printing inkdescribed is blended with a white titanium dioxide intaglio printing inkin a manner such that the colored and white pigments are present in aratio of 1:20. The printing ink thus prepared is printed on an intaglioprinting machine. For deter mining the intensity of the prints, theprints are compared with a color intensity scale. As comparativepigments for this scale a disazo dyestuff is used being prepared withoutapplying the additives according to the process of the presentinvention. This test proves that the intensity of the prints obtainedwith the disazo dyestuff treated according to the process of the presentinvention is distinctly higher and in a clear greenish shade whencompared to the intensity of prints obtained with an untreated dyestuff.

EXAMPLE 2 If in Example 1 the mixing proportion of the auxiliary ischanged in favor of the aminoxide, that means if a mixture consisting of14.1 parts of tallow fat propylene diamine and 47 parts of an aqueoussolution of coconut oil dimethyl-aminox ide of 30 percent strength isused instead of the mixture described, the intensity of shade achievedwith the printing inks prepared with the dyestuff according to thepresent invention is even higher, the good rheologic properties beingthe same.

EXAMPLE 3 When using in Example 1, instead of the mixture of theauxiliary described, a mixture consisting of 15 parts of tallow fatpropylene diamine and 15.8 parts of an aqueous solution of coconut oildimethyl-aminoxide of 30.4 percent strength, the product thus obtainedyields a further increase of the tinctorial strength without the goodrheologic properties of the printing inks prepared therefrom beingimpaired.

Furthermore, one may proceed with the auxiliary according to the presentinvention in such manner that the components of the mixture are appliedone after another, thus, that the 15.8 parts of an aqueous solution ofcoconut oil dimethylaminoxide of 30.4 percent strength are added, forexample, to the precipitated coupling component prior to the addition ofthe tetrazonium salt solution, whereas the 15 parts of tallow fatpropylene diamine are introduced in the coupling mixture during theheating operation at 60 C.

EXAMPLE 4 Instead of the mixture of the auxiliary mentioned in Example 1there may be added, during the inflow of the tetrazonium salt solutionto the coupling component, a 5 percent aqueous solution of 15 parts ofcoconut oil aminacetate and subsequently a mixture consisting of 13.5parts of tallow fat propylene diamine and 1.5 parts of coconut oildimethylaminoxide in form of a 10 percent aqueous emulsion.

EXAMPLE 5 Tetrazotization and coupling is carried out as described inExample 1. A mixture heated to 65 C. and consisting of 228 parts oftallow fat propylene diamine and 76 parts of a 10 percent aqueoussolution of dodecyl-dimethyl-phosphine oxide is added to the couplingmixture during the heating operation, prior to boiling at 60 C. Furtherworking procedure cor responds to that described in Example 1.

The dyestuff obtained by this method has practically the same goodcolouristic properties, such as tinctorial strength and shade, andrheologic qualities as the product obtained according to Example 1.

Instead of the dodecyl-dimethyl-phosphine oxide there may be used asmixing component with the fat amines in the auxiliaries according to thepresent invention, equivalent quanti ties of the following phosphineoxides having practically the same effect, such as for instance coconutoil diethyl-phosphine-oxide, olely-dimethyl-phosphine-oxide, tallow fatdimethyl-phosphine-oxide.

EXAMPLE 6 A tetrazonium salt solution prepared in known manner from 253parts of 3,3'-dichloro-4,4-diamino-diphenyl is allowed to flow, within 2hours, to a coupling component, which was prepared by dissolving 390parts of l-(acetoacetylamino)-2- methyl-benzene in 8,000 parts of waterand 382 parts ofa 33 percent sodium hydroxide solution. Then, 56 partsof an aqueous solution of coconut oil dimethyl-aminoxide of 30.4 percentstrength, diluted with water in a ratio of 1:1 are added. The couplingcomponent is subsequently precipitated by adding 210 parts of aceticacid. When coupling is terminated, the mixture is after-stirred forminutes and heated, within 1 hour, to boil. As soon as the temperatureattains 60 C., 95 parts of tallow fat propylene diamine are added. Thewhole is boiled for 15 minutes, cooled with water to 80 C. and then 449parts of a 33 percent sodium hydroxide solution are added. After havingstirred for another 10 minutes, the product is filtered, washed toneutral and the dyestuff is dried at 60 C. i

The dyestuff thus obtained produces, when incorporated in a commercialintaglio printing ink and blended with titanium dioxide-as described inExample l-and printed on an intaglio printing machine, prints having anessentially higher tinctorial strength and distinctly greener, purershades than those prints, obtained by a same dyestuff prepared, however,without addition of coconut fat dimethyl-aminoxide and tallow fatpropylene diamine.

Another important advantage of a pigment prepared according to theforegoing Example is that the intaglio printing inks made therefrom havea far better flowability compared to a pigment coupled without theaforementioned additives.

The same good result is obtained when, instead of the aforementionedadditions, at 60 C. during the heating operation a mixture heated to 65C. is added which consists of 95 parts of tallow fat propylene diamineand 31.5 parts of an aqueous solution of coconut oil dimethyl-aminoxideof 30.4 percent strength. The procedure continues as described before.

We claim:

1. in a process for preparing a water-insoluble azo-dyestuff by couplinga diazonium compound component and a coupling compound component in acoupling mixture thereof, the improvement which comprises adding to saidcoupling mixture an auxiliary mixture consisting essentially of 1) fromabout 95 to about 50 parts by weight of a primary aliphatic amine of theformula in which A is -C,.H or -C,.H n is zero or an integer from 7 to22, m is zero or an integer from I to 6,

p is an integer 2 or 3, provided the sum of n and m is greater thanzero, or an acid addition salt of said primary amine and a low molecularweight carboxylic acid of the group consisting of formic, acetic,propionic, lactic and oleic acids, (2) from about 5 to about 50 parts byweight of an aminoxide or a phosphinoxide that contains (a) one groupthat is a saturated or an olefinic aliphatic hydrocarbon of 8v to about22 carbon atoms, or is phenyl or benzyl substituted by a saturated or anolefinic aliphatic hydrocarbon of 4 to about I2 carbon atoms, (b) onegroup that is an alkyl of l to 5 carbon atoms, cyclohexyl, phenyl,benzyl, or a saturated or an olefinic aliphatic hydrocarbon of 8 to 22carbon atoms, and (c) one group that is an alkyl of l to 5 carbon atoms,cyclohexyl, phenyl or benzyl, said auxiliary mixture being used in anamount of from about 1% to about 35% by weight of the azodyestuff ofsaid coupling mixture.

2. A process according to claim 1 wherein said auxiliary mixture is usedin an amount of from about 3 percent to about 17 ercent.

A process according to claim 1 wherein said auxiliary mixture containsfrom about to about 70 parts of component (1) and from about 5 to about30 parts of component (2).

4. A process according to claim 1 wherein said aminoxide orphosphinoxide is of the formula in which X is a nitrogen or phosphorusatom, R is an alkyl or alkenyl group of 8 to 22 carbon atoms, and R andR each is an alkyl of 1 to 5 carbon atoms, cyclohexyl, phenyl or benzylgroup.

5. A process according to claim I wherein said aminoxide contains onealkyl group of 8 to 22 carbon atoms and two alkyl groups each of l to 5carbon atoms.

6. A process according to claim 1 wherein said phosphinoxide containsone alkyl group of 8 to 22 carbon atoms and two alkyl groups each of lto 5 carbon atoms.

7. A process according to claim 1 wherein said amine (l) is capryl-,lauryl-, palmityl-, stearyl-, oleyl-, arachyl-, behenyl-, tallow fat orcoconut oil amine, ethylene-, propylene-, tallow fat ethylene-, tallowfat propyleneor coconut oil ethylenediamine, diethyleneordipropylene-triamine, stearyltriethylene-tetramine orpentaethylene-hexamine, and said oxide (2) is dodecyl-dimethyl-,oleyl-diethyl-, lauryl-methylethyl-, coconut oil-dimethyl-, coconutoil-dipropyl-, coconut oil-methyl-benzyl-, oleyl-propyl-methyl-,dodecyl-ethylcyclohexyl-or tallow fat-dimethyl-aminoxide ordodecyldimethyl-, dodecyl-diethyl-, dodecyl-methyl-ethyl-,dodecylmethyl-benzyl-, oleyldimethyl-, oleyl-dibenzyl-, tallowfatdimethylor coconut oil-diethyl-phosphinoxide.

2. A process according to claim 1 wherein said auxiliary mixture is usedin an amount of from about 3 percent to about 17 percent.
 3. A processaccording to claim 1 wherein said auxiliary mixture contains from about95 to about 70 parts of component (1) and from about 5 to about 30 partsof component (2).
 4. A process according to claim 1 wherein saidaminoxide or phosphinoxide is of the formula in which X is a nitrogen orphosphorus atom, R1 is an alkyl or alkenyl group of 8 to 22 carbonatoms, and R2 and R3 each is an alkyl of 1 to 5 carbon atoms,cyclohexyl, phenyl or benzyl group.
 5. A process according to claim 1wherein said aminoxide contains one alkyl group of 8 to 22 carbon atomsand two alkyl groups each of 1 to 5 carbon atoms.
 6. A process accordingto claim 1 wherein said phosphinoxide contains one alkyl group of 8 to22 carbon atoms and two alkyl groups each of 1 to 5 carbon atoms.